A histopathologic and radiographic study using excessive occlusal forces to create injury in the tissues of the periodontium and temporomandibular joint is being conducted in rhesus monkeys. The forces will be measured using a multiple force transducer that was designed specifically for this purpose. This method of instrumentation will help us define the role of trauma from occlusion in chronic periodontal disease by enabling us to quantitate and correlate the magnitude, direction, and duration of the force with the location and extent of the injury. The response of the periodontium and temporomandibular joint to the alleviation of these excessive forces will also be studied.